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comparison: media/libvorbis/lib/vorbis_envelope.c

media/libvorbis/lib/vorbis_envelope.c

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1 /********************************************************************
2 * *
3 * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
4 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
5 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
6 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
7 * *
8 * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009 *
9 * by the Xiph.Org Foundation http://www.xiph.org/ *
10 * *
11 ********************************************************************
12
13 function: PCM data envelope analysis
14 last mod: $Id: envelope.c 16227 2009-07-08 06:58:46Z xiphmont $
15
16 ********************************************************************/
17
18 #include <stdlib.h>
19 #include <string.h>
20 #include <stdio.h>
21 #include <math.h>
22 #include <ogg/ogg.h>
23 #include "vorbis/codec.h"
24 #include "codec_internal.h"
25
26 #include "os.h"
27 #include "scales.h"
28 #include "envelope.h"
29 #include "mdct.h"
30 #include "misc.h"
31
32 void _ve_envelope_init(envelope_lookup *e,vorbis_info *vi){
33 codec_setup_info *ci=vi->codec_setup;
34 vorbis_info_psy_global *gi=&ci->psy_g_param;
35 int ch=vi->channels;
36 int i,j;
37 int n=e->winlength=128;
38 e->searchstep=64; /* not random */
39
40 e->minenergy=gi->preecho_minenergy;
41 e->ch=ch;
42 e->storage=128;
43 e->cursor=ci->blocksizes[1]/2;
44 e->mdct_win=_ogg_calloc(n,sizeof(*e->mdct_win));
45 mdct_init(&e->mdct,n);
46
47 for(i=0;i<n;i++){
48 e->mdct_win[i]=sin(i/(n-1.)*M_PI);
49 e->mdct_win[i]*=e->mdct_win[i];
50 }
51
52 /* magic follows */
53 e->band[0].begin=2; e->band[0].end=4;
54 e->band[1].begin=4; e->band[1].end=5;
55 e->band[2].begin=6; e->band[2].end=6;
56 e->band[3].begin=9; e->band[3].end=8;
57 e->band[4].begin=13; e->band[4].end=8;
58 e->band[5].begin=17; e->band[5].end=8;
59 e->band[6].begin=22; e->band[6].end=8;
60
61 for(j=0;j<VE_BANDS;j++){
62 n=e->band[j].end;
63 e->band[j].window=_ogg_malloc(n*sizeof(*e->band[0].window));
64 for(i=0;i<n;i++){
65 e->band[j].window[i]=sin((i+.5)/n*M_PI);
66 e->band[j].total+=e->band[j].window[i];
67 }
68 e->band[j].total=1./e->band[j].total;
69 }
70
71 e->filter=_ogg_calloc(VE_BANDS*ch,sizeof(*e->filter));
72 e->mark=_ogg_calloc(e->storage,sizeof(*e->mark));
73
74 }
75
76 void _ve_envelope_clear(envelope_lookup *e){
77 int i;
78 mdct_clear(&e->mdct);
79 for(i=0;i<VE_BANDS;i++)
80 _ogg_free(e->band[i].window);
81 _ogg_free(e->mdct_win);
82 _ogg_free(e->filter);
83 _ogg_free(e->mark);
84 memset(e,0,sizeof(*e));
85 }
86
87 /* fairly straight threshhold-by-band based until we find something
88 that works better and isn't patented. */
89
90 static int _ve_amp(envelope_lookup *ve,
91 vorbis_info_psy_global *gi,
92 float *data,
93 envelope_band *bands,
94 envelope_filter_state *filters){
95 long n=ve->winlength;
96 int ret=0;
97 long i,j;
98 float decay;
99
100 /* we want to have a 'minimum bar' for energy, else we're just
101 basing blocks on quantization noise that outweighs the signal
102 itself (for low power signals) */
103
104 float minV=ve->minenergy;
105 float *vec=alloca(n*sizeof(*vec));
106
107 /* stretch is used to gradually lengthen the number of windows
108 considered prevoius-to-potential-trigger */
109 int stretch=max(VE_MINSTRETCH,ve->stretch/2);
110 float penalty=gi->stretch_penalty-(ve->stretch/2-VE_MINSTRETCH);
111 if(penalty<0.f)penalty=0.f;
112 if(penalty>gi->stretch_penalty)penalty=gi->stretch_penalty;
113
114 /*_analysis_output_always("lpcm",seq2,data,n,0,0,
115 totalshift+pos*ve->searchstep);*/
116
117 /* window and transform */
118 for(i=0;i<n;i++)
119 vec[i]=data[i]*ve->mdct_win[i];
120 mdct_forward(&ve->mdct,vec,vec);
121
122 /*_analysis_output_always("mdct",seq2,vec,n/2,0,1,0); */
123
124 /* near-DC spreading function; this has nothing to do with
125 psychoacoustics, just sidelobe leakage and window size */
126 {
127 float temp=vec[0]*vec[0]+.7*vec[1]*vec[1]+.2*vec[2]*vec[2];
128 int ptr=filters->nearptr;
129
130 /* the accumulation is regularly refreshed from scratch to avoid
131 floating point creep */
132 if(ptr==0){
133 decay=filters->nearDC_acc=filters->nearDC_partialacc+temp;
134 filters->nearDC_partialacc=temp;
135 }else{
136 decay=filters->nearDC_acc+=temp;
137 filters->nearDC_partialacc+=temp;
138 }
139 filters->nearDC_acc-=filters->nearDC[ptr];
140 filters->nearDC[ptr]=temp;
141
142 decay*=(1./(VE_NEARDC+1));
143 filters->nearptr++;
144 if(filters->nearptr>=VE_NEARDC)filters->nearptr=0;
145 decay=todB(&decay)*.5-15.f;
146 }
147
148 /* perform spreading and limiting, also smooth the spectrum. yes,
149 the MDCT results in all real coefficients, but it still *behaves*
150 like real/imaginary pairs */
151 for(i=0;i<n/2;i+=2){
152 float val=vec[i]*vec[i]+vec[i+1]*vec[i+1];
153 val=todB(&val)*.5f;
154 if(val<decay)val=decay;
155 if(val<minV)val=minV;
156 vec[i>>1]=val;
157 decay-=8.;
158 }
159
160 /*_analysis_output_always("spread",seq2++,vec,n/4,0,0,0);*/
161
162 /* perform preecho/postecho triggering by band */
163 for(j=0;j<VE_BANDS;j++){
164 float acc=0.;
165 float valmax,valmin;
166
167 /* accumulate amplitude */
168 for(i=0;i<bands[j].end;i++)
169 acc+=vec[i+bands[j].begin]*bands[j].window[i];
170
171 acc*=bands[j].total;
172
173 /* convert amplitude to delta */
174 {
175 int p,this=filters[j].ampptr;
176 float postmax,postmin,premax=-99999.f,premin=99999.f;
177
178 p=this;
179 p--;
180 if(p<0)p+=VE_AMP;
181 postmax=max(acc,filters[j].ampbuf[p]);
182 postmin=min(acc,filters[j].ampbuf[p]);
183
184 for(i=0;i<stretch;i++){
185 p--;
186 if(p<0)p+=VE_AMP;
187 premax=max(premax,filters[j].ampbuf[p]);
188 premin=min(premin,filters[j].ampbuf[p]);
189 }
190
191 valmin=postmin-premin;
192 valmax=postmax-premax;
193
194 /*filters[j].markers[pos]=valmax;*/
195 filters[j].ampbuf[this]=acc;
196 filters[j].ampptr++;
197 if(filters[j].ampptr>=VE_AMP)filters[j].ampptr=0;
198 }
199
200 /* look at min/max, decide trigger */
201 if(valmax>gi->preecho_thresh[j]+penalty){
202 ret|=1;
203 ret|=4;
204 }
205 if(valmin<gi->postecho_thresh[j]-penalty)ret|=2;
206 }
207
208 return(ret);
209 }
210
211 #if 0
212 static int seq=0;
213 static ogg_int64_t totalshift=-1024;
214 #endif
215
216 long _ve_envelope_search(vorbis_dsp_state *v){
217 vorbis_info *vi=v->vi;
218 codec_setup_info *ci=vi->codec_setup;
219 vorbis_info_psy_global *gi=&ci->psy_g_param;
220 envelope_lookup *ve=((private_state *)(v->backend_state))->ve;
221 long i,j;
222
223 int first=ve->current/ve->searchstep;
224 int last=v->pcm_current/ve->searchstep-VE_WIN;
225 if(first<0)first=0;
226
227 /* make sure we have enough storage to match the PCM */
228 if(last+VE_WIN+VE_POST>ve->storage){
229 ve->storage=last+VE_WIN+VE_POST; /* be sure */
230 ve->mark=_ogg_realloc(ve->mark,ve->storage*sizeof(*ve->mark));
231 }
232
233 for(j=first;j<last;j++){
234 int ret=0;
235
236 ve->stretch++;
237 if(ve->stretch>VE_MAXSTRETCH*2)
238 ve->stretch=VE_MAXSTRETCH*2;
239
240 for(i=0;i<ve->ch;i++){
241 float *pcm=v->pcm[i]+ve->searchstep*(j);
242 ret|=_ve_amp(ve,gi,pcm,ve->band,ve->filter+i*VE_BANDS);
243 }
244
245 ve->mark[j+VE_POST]=0;
246 if(ret&1){
247 ve->mark[j]=1;
248 ve->mark[j+1]=1;
249 }
250
251 if(ret&2){
252 ve->mark[j]=1;
253 if(j>0)ve->mark[j-1]=1;
254 }
255
256 if(ret&4)ve->stretch=-1;
257 }
258
259 ve->current=last*ve->searchstep;
260
261 {
262 long centerW=v->centerW;
263 long testW=
264 centerW+
265 ci->blocksizes[v->W]/4+
266 ci->blocksizes[1]/2+
267 ci->blocksizes[0]/4;
268
269 j=ve->cursor;
270
271 while(j<ve->current-(ve->searchstep)){/* account for postecho
272 working back one window */
273 if(j>=testW)return(1);
274
275 ve->cursor=j;
276
277 if(ve->mark[j/ve->searchstep]){
278 if(j>centerW){
279
280 #if 0
281 if(j>ve->curmark){
282 float *marker=alloca(v->pcm_current*sizeof(*marker));
283 int l,m;
284 memset(marker,0,sizeof(*marker)*v->pcm_current);
285 fprintf(stderr,"mark! seq=%d, cursor:%fs time:%fs\n",
286 seq,
287 (totalshift+ve->cursor)/44100.,
288 (totalshift+j)/44100.);
289 _analysis_output_always("pcmL",seq,v->pcm[0],v->pcm_current,0,0,totalshift);
290 _analysis_output_always("pcmR",seq,v->pcm[1],v->pcm_current,0,0,totalshift);
291
292 _analysis_output_always("markL",seq,v->pcm[0],j,0,0,totalshift);
293 _analysis_output_always("markR",seq,v->pcm[1],j,0,0,totalshift);
294
295 for(m=0;m<VE_BANDS;m++){
296 char buf[80];
297 sprintf(buf,"delL%d",m);
298 for(l=0;l<last;l++)marker[l*ve->searchstep]=ve->filter[m].markers[l]*.1;
299 _analysis_output_always(buf,seq,marker,v->pcm_current,0,0,totalshift);
300 }
301
302 for(m=0;m<VE_BANDS;m++){
303 char buf[80];
304 sprintf(buf,"delR%d",m);
305 for(l=0;l<last;l++)marker[l*ve->searchstep]=ve->filter[m+VE_BANDS].markers[l]*.1;
306 _analysis_output_always(buf,seq,marker,v->pcm_current,0,0,totalshift);
307 }
308
309 for(l=0;l<last;l++)marker[l*ve->searchstep]=ve->mark[l]*.4;
310 _analysis_output_always("mark",seq,marker,v->pcm_current,0,0,totalshift);
311
312
313 seq++;
314
315 }
316 #endif
317
318 ve->curmark=j;
319 if(j>=testW)return(1);
320 return(0);
321 }
322 }
323 j+=ve->searchstep;
324 }
325 }
326
327 return(-1);
328 }
329
330 int _ve_envelope_mark(vorbis_dsp_state *v){
331 envelope_lookup *ve=((private_state *)(v->backend_state))->ve;
332 vorbis_info *vi=v->vi;
333 codec_setup_info *ci=vi->codec_setup;
334 long centerW=v->centerW;
335 long beginW=centerW-ci->blocksizes[v->W]/4;
336 long endW=centerW+ci->blocksizes[v->W]/4;
337 if(v->W){
338 beginW-=ci->blocksizes[v->lW]/4;
339 endW+=ci->blocksizes[v->nW]/4;
340 }else{
341 beginW-=ci->blocksizes[0]/4;
342 endW+=ci->blocksizes[0]/4;
343 }
344
345 if(ve->curmark>=beginW && ve->curmark<endW)return(1);
346 {
347 long first=beginW/ve->searchstep;
348 long last=endW/ve->searchstep;
349 long i;
350 for(i=first;i<last;i++)
351 if(ve->mark[i])return(1);
352 }
353 return(0);
354 }
355
356 void _ve_envelope_shift(envelope_lookup *e,long shift){
357 int smallsize=e->current/e->searchstep+VE_POST; /* adjust for placing marks
358 ahead of ve->current */
359 int smallshift=shift/e->searchstep;
360
361 memmove(e->mark,e->mark+smallshift,(smallsize-smallshift)*sizeof(*e->mark));
362
363 #if 0
364 for(i=0;i<VE_BANDS*e->ch;i++)
365 memmove(e->filter[i].markers,
366 e->filter[i].markers+smallshift,
367 (1024-smallshift)*sizeof(*(*e->filter).markers));
368 totalshift+=shift;
369 #endif
370
371 e->current-=shift;
372 if(e->curmark>=0)
373 e->curmark-=shift;
374 e->cursor-=shift;
375 }

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